Automated solution maker apparatus

ABSTRACT

An automated solution maker is provided. The automated solution maker mixes a chemical with a solvent to a desired concentration. The concentration of the solution is monitored by measuring the conductivity of the solution. Based upon this measurement, the concentration of the solution may be adjusted.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. patent applicationSer. No. 11/190,395 filed on Jul. 27, 2005. The subject matter of theforegoing is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to an apparatus used to produce chemicalsolutions such as a brine solution. More specifically, the inventionrelates to an automated apparatus for dissolving a chemical in a solventto produce a solution of a specific concentration.

BACKGROUND OF THE INVENTION

The application of a salt solution to reduce the amount of snow and icefrom roads, sidewalks, driveways and other surfaces is a commonindustrial practice. Salt solution is generally created by mixing rocksalt and water to produce a solution. The concentration of the solutionmay then adjusted by adding fresh water to dilute the mixture or addingsalt to concentrate the mixture. A solution of approximately 23-27% byweight is efficient for removing ice and snow (where sodium chloride isthe salt). At this concentration range, the solution will melt ice andsnow with an ambient temperature of approximately −10 degreesFahrenheit. If the desired concentration is not maintained in thesolution and applied in the correct amounts on the streets, accidentsmay occur.

One method of monitoring and adjusting the concentration of a solutionis to measure the specific gravity of the solution and add fresh waterto the solution until a desired specific gravity is met. This methodthus correlates the specific gravity of the solution with theconcentration of the solution. U.S. Pat. No. 6,439,252 discloses anapparatus and method for automatically producing large quantities ofdissolved rock salt or calcium magnesium acetate (CMA) pellets in waterfor producing a salt solution to be used as a liquid deicer to be usedfor spraying roadways, sidewalks, driveways, and runways to melt snowand ice. An electronic hydrometer (a specific gravity measuring device)measures the specific gravity of the brine/water solution. If thespecific gravity is too high or too low a valve is opened or closed toadjust the amount of fresh water to the mixture. In this manner themixture is automatically adjusted to the salinity desired.

As mentioned above, methods for producing salt solutions that usespecific gravity as an indicator of concentration correlate specificgravity to concentration. This correlation can, in some instances, befaulty. For example, solids such as silica, dirt, and other foreignmaterial in the solution can affect the specific gravity of the solutionand/or the reading of the measuring device. This may in turn lead to anundesired salt concentration level for the solution. In addition,measurements based on specific gravity generally are a series ofseparate measurements, spaced apart in time and process, rather than acontinuous measurement as the progress proceeds.

Therefore, there is a need in the art for an apparatus and method thatproduces an accurate salt concentration level for a salt solution thatis not dependent on measuring the solution's specific gravity.

BRIEF SUMMARY OF THE INVENTION

An automated apparatus for producing a solution comprising a hopperadapted to receive a chemical and a solvent, the chemical and solventmixing to form a solution, a solution sensor for sensing a conductivityof the solution and correlating the conductivity to a concentration ofthe solution, and a controller for affecting the concentration of thesolution based upon the sensed conductivity. More specifically, if theconcentration is over a target concentration, the controller operates todecrease the concentration of the solution, if the concentration isbelow a target concentration, the controller operates to increase theconcentration of the solution, and if the concentration is within atolerance of the target concentration, the controller operates to divertthe solution to a storage tank.

In one embodiment, the automated apparatus for producing a solution isan automated brine maker. The hopper is adapted to receive sodiumchloride and fresh water. The sodium chloride is at least partiallydissolved in the fresh water in the hopper to form brine. A solutionsensor detects a conductivity of the solution at a measured temperatureand correlates the conductivity of the solution at that temperature to aconcentration curve for sodium chloride in fresh water, therebydetermining a concentration of the solution. A controller operates toadjust the concentration of the solution based upon the determinedconcentration, as appropriate. If the concentration is over a targetconcentration, the controller adds fresh water to the solution. If theconcentration is under a target concentration, the controller returnsthe solution to the hopper and more sodium chloride is dissolved in thesolution. If the concentration is within a tolerance of the targetconcentration, the controller diverts the solution to a storage tank.

While multiple embodiments are disclosed, still other embodiments of theinvention will become apparent to those skilled in the art from thefollowing detailed description, which shows and describes illustrativeembodiments of the invention. As will be realized, the invention iscapable of modifications in various obvious aspects, all withoutdeparting from the spirit and scope of the invention. Accordingly, thedrawings and detailed description are to be regarded as illustrative innature and not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of an automated solution maker inaccordance with one embodiment of the present invention.

FIG. 2 illustrates a front view of a hopper of an automated solutionmaker in accordance with one embodiment of the present invention.

FIG. 3 illustrates a cutaway front view of a hopper of an automatedsolution maker in accordance with one embodiment of the presentinvention.

FIG. 4 illustrates a cutaway perspective view of a hopper of anautomated solution maker in accordance with one embodiment of thepresent invention.

FIG. 5 illustrates an inside cutaway view of hopper of an automatedsolution maker in accordance with one embodiment of the presentinvention.

FIG. 6 illustrates an interior view of a hopper of an automated solutionmaker in accordance with one embodiment of the present invention.

FIG. 7 illustrates a rear view of a hopper of an automated solutionmaker in accordance with one embodiment of the present invention.

FIG. 8 illustrates an end view of a hopper of an automated solutionmaker in accordance with one embodiment of the present invention.

FIG. 9 illustrates a cutaway end view of a hopper of an automatedsolution maker in accordance with one embodiment of the presentinvention.

FIG. 10 illustrates a grate of an automated solution maker in accordancewith one embodiment of the present invention.

FIG. 11 illustrates a control panel of an automated solution maker inaccordance with one embodiment of the present invention.

FIG. 12 illustrates a control panel and mechanical components of anautomated solution maker in accordance with one embodiment of thepresent invention.

FIG. 13 illustrates a control manifold with programmable logiccontroller and human-machine interface of an automated solution maker inaccordance with one embodiment of the present invention.

FIG. 14 illustrates flow of an automated solution maker in accordancewith one embodiment of the present invention.

FIG. 15 illustrates a perspective view of an automated solution makerand control panel in accordance with one embodiment of the presentinvention.

FIG. 16 illustrates a perspective view of a float assembly in accordancewith one embodiment of the present invention.

FIG. 17 illustrates solvent being added to a first portion of anautomated solution maker in accordance with one embodiment of thepresent invention.

FIG. 18 illustrates mixing of solvent with chemical in a first portionof an automated solution maker in accordance with one embodiment of thepresent invention.

FIG. 19 illustrates an inside view of a first portion of an automatedsolution maker in accordance with one embodiment of the presentinvention.

FIG. 20 illustrates an inside view of a first portion of an automatedsolution maker in accordance with one embodiment of the presentinvention.

FIG. 21 illustrates an inside view of a second portion of an automatedsolution maker in accordance with one embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

An automated solution maker is provided. More specifically, the presentinvention provides an apparatus and method of producing a solution, suchas a salt solution, with a desired concentration by measuring theconductivity of the solution, determining an amount of solvent to beadded to the solution, and adding the amount of solvent to the solution.The device may further be configured to separate sediment from thechemical and solvent and flush out deposited sediments. Thus, the devicemay be configured for separating foreign material such as undissolvedsilica, dirt, and gravel from the solution.

In one embodiment, the automated solution maker may be configured forproducing a clean brine solution by dissolving salt into water. Theautomated solution maker produces a brine solution having aconcentration of a desired target concentration, or equal to or greaterthan a target concentration.

As shown in FIGS. 1 through 3, one embodiment of an automated solutionmaker 100 comprises a hopper 102 having a first portion 104 and a secondportion 106. An example suitable capacity for the hopper 102 is fivecubic yards. The first portion 104 and the second portion 106 areseparated by a grate 142. The first portion 104 is adapted to receive achemical for dissolution in a solvent to produce a solution. To producea brine solution, the component may be, for example, sodium chloride(NaCl or salt) or calcium magnesium sulfate. The chemical may beprovided in any suitable form. For example, if the chemical is salt, itmay be provided in pellet or rock form. Other components may be used toproduce other solutions. As will be discussed more fully below, theautomated solution maker may be calibrated for use with differentchemicals or solvents to produce different solutions. In one embodiment,the automated solution maker mixes sodium chloride and fresh water toproduce a brine solution. The chemical in the first portion may providea chemical bed. For example, in producing a brine solution, a salt bedmay be formed in the first portion 104.

The first portion 104 is further adapted to receive a solvent formixture with the chemical to produce the desired solution. The automatedbrine maker is downward flowing and the solvent passes through thechemical bed in the first portion 104 due to the force of gravity. Thesolvent may be delivered to the first portion 104 in any suitablemanner. A solvent line leading to the hopper may be provided. Aself-regulating heating element may be coupled to the solvent line toprotect against freezing of the solvent. In the embodiment of FIG. 1,the solvent is delivered via a solvent valve 136 that actuates flow froma solvent inlet 138. The solvent valve 136 may be provided as anelectric actuated valve and valve actuation may be controlled by aprogrammable logic controller (PLC) 216 (see FIG. 12). Actuation maydepend on one or more liquid level sensors. As discussed more fullybelow and shown in FIG. 3, a first liquid level sensor 118, a secondliquid level sensor 120, and a third liquid level sensor 122 may beprovided. As shown in FIGS. 8, 12, and 19, in a specific embodiment, thesolvent inlet 138 may be pressurized and may supply solvent to theautomated solution maker 100 via a solvent valve 136, conduit 200,manual valve 186, manual valve 158, conduit 176 and spray head 178 toautomated dilute valve 134. The fresh solvent valve 136 may furthercomprise a manual override. Of course, while a specific embodiment isherein described, an automated solution maker within the scope of thepresent invention may include fewer or more component parts as would beunderstood by one skilled in the art.

A grate 142 substantially prevents the chemical from passing from thefirst portion 104 of the hopper 102 to the second portion 106 of thehopper 102 before the chemical is dissolved in the solvent. Perforationsmay be provided in the grate 142. When a solution comprising the solventand dissolved chemical is formed in the first portion 104, theperforations in the grate 142 allow the solution to pass through thegrate 142 into the second portion 106 of the hopper 102. FIG. 5illustrates one embodiment of a grate 142 suitable for use with theautomated solution maker. As shown, the grate 142 may comprise aplurality of annular perforations 143. The perforations 143 may beapproximately 3/16 inch diameter. Desirably, the perforations 143 arelarge enough to permit even flow of the solution through the grate 142but small enough to prevent the chemical from passing through the grate142. Thus, the grate 142 operates to support the chemical, collectdebris, and allow passage of solution. In one embodiment, the grate 142is nonmetallic and comprises 1½ inch fiberglass structural crossmembers.

FIGS. 19 and 20 show the inside of a first portion 104 of an automatedsolution maker. In FIG. 19, spray heads 178 for expelling solvent andgrate 142 may be seen. FIG. 20 shows flow through the spray heads 178.

As stated above, one or more liquid level sensors may be provided. Theliquid level sensors are liquid level sensing devices. They may beprovided with switches that send a signal to the PLC 216. As such, theliquid level sensors may be operably connected to inputs of the PLC 216.The liquid level sensors may be provided as any suitable device. In oneembodiment, a suitable liquid level sensor is a mechanical switch with afloat device that activates a micro switch. In another embodiment, aninductive capacitive proximity switch may be used. The liquid levelsensors maintain liquid levels in the hopper, and more specifically inthe first portion of the hopper, at a desired level. Generally, highwater levels may overfill the hopper and create a spill while low waterlevels may cause a transfer pump 124 to run dry and thereby damage thepump seals.

As shown in FIG. 3, first, second, and third liquid level sensors 118,120, and 122, respectively, are provided. Reference is made to FIGS. 7and 9 to further illustrate the liquid level sensors. In someembodiments, more than three liquid level sensors may be provided.Alternately, no liquid level sensors may be provided. The first liquidlevel sensor 118 abuts the hopper 102 and is generally adjacent to thesecond liquid level sensor 120 and may be connected to an input of thePLC 216. The first liquid level sensor 118 detects if the water level inhopper 102 is low. If the liquid level is low and the automated solutionmaker 100 is in run mode, a pump 124 is turned to an “off” state if theautomated brine maker 100 is in run mode. This protects pump 124 fromdamage caused by running dry.

The second liquid level sensor 120 is generally adjacent to the firstliquid level sensor 118 and the third liquid level sensor 122 and may beconnected to an input of the PLC 216. The second liquid level sensor 120detects if an adequate amount of water is present in the hopper 102.Based on the detection of an adequate amount of solvent, the pump 124 isactivated and switched to an “on” state. The pump 124 is latched intothe “on” state until the batch is completed or the first liquid levelsensor 118 detects that the liquid level is low.

The third liquid level sensor 122 abuts the hopper 102 and is generallyadjacent to the second liquid level sensor 120 and may be connected toan input of the PLC 216. The third liquid level sensor 122 detects ifthe hopper 102 is holding a predetermined level of liquid. If this levelof liquid is sensed, the solvent valve 136 is switched into the “off”position, thus protecting the hopper 102 from overflowing.

The second portion 106 of the hopper 102 comprises a brine solutionsuction tube 164 connected to a conduit 148 and a brine outlet valve154. The brine outlet valve 154 is connected to the transfer pump 124via an outlet conduit 148. A solvent dilute inlet 146 and a pump suctioninlet may be connected to the conduit 148. As shown, the pump 124 may beprovided in communication with a solution sensor 132. In one embodiment,the solution sensor 132 is a conductivity and temperature sensor of theterodial type. Such a sensor is solid state with no contact points andmeasures the inductive field of the solution. In one embodiment, thesolution sensor 132 senses the conductivity and the temperature of thesolution. In another embodiment, the solution sensor 132 senses only theconductivity of the solution. The solution sensor 132 may comprise aprobe and conductivity analyzer. The solution sensor 132 measures theelectrical resistance of the solution flowing across the solution sensor132. The solution sensor 132 may be configured to measure continuously,thus providing constant input rather than periodic snapshots to the PLC216, thereby increasing the efficiency of the machine.

Alternatively, a refractometer can be used in place of the solutionsensor 132. The refractive properties of the solution vary base onconcentration. The refractometer detects the refractive index of thesolution, and the PLC 216 then is able to calculate, and adjust, theconcentration as appropriate.

In one embodiment, the electrical resistance is compared to thetemperature of the solution and these two variables are equated to forma temperature compensated conductivity reading. This reading is equatedto a concentration curve which in turn expresses the reading of thesolution as a temperature compensated concentration by weight. Aconcentration curve correlating temperature compensated conductivity toconcentration may be developed for any chemicals in solution. Thus, forexample, in an automated brine maker, a sodium chloride concentrationcurve is used. As stated above, in one embodiment, the solution sensormeasures the temperature and the conductivity of the solution. Theproperties of brine change with temperature and, thus, it may bedesirable to measure the temperature to formulate the actualconcentration. As will be discussed more fully below, solution that isoutside of a tolerance of a target concentration may be adjusted whilesolution that is within a tolerance of a target concentration may beprocessed to a storage tank. By measuring and adjusting theconcentration midstream, the automated solution maker produces solutioncontinuously at a target concentration without the intervention of anoperator.

With reference to FIGS. 1, 12, and 13, the solution sensor 132 may be inoperable communication with the PLC 216. In response to the determinedconcentration, the PLC 216 may activate a dilute valve 134 or a divertervalve 130 to ensure that only solution of a desired concentration isdiverted to a storage tank. The target concentration of the solution maybe any desired concentration. For brine solutions, a suitable targetconcentration may be in the range of 19.6 to 27% by weight. For example,the target concentration may be 23.3% by weight. In addition toestablishing a desired solution concentration, a desired solutionconcentration tolerance may be established wherein a certain variancefrom the desired solution concentration is considered acceptable. Anacceptable tolerance may be +/−0.3% of the target concentration.

The diverter valve 130 diverts flow from the pump 124 through a returntube 126 if the solution concentration is above or below the targetconcentration or through a finished product tube 128 if the solutionconcentration is within the approximately the desired solutionconcentration. The diverter valve 130 is controlled by the PLC 216 anddepends on the target versus actual concentration. Solution that isoutside of a tolerance of the target concentration may be diverted toconduit 126, valve 156, conduit 180, and agitation nozzles 166 for afurther pass through the hopper 104. Again, while specific embodiment ofa diverting mechanism is provided, alternate mechanisms as would beknown to one skilled in the art may be used for diverting solutionoutside of a tolerance of a target concentration to the hopper.

The return tube 126 passes flow to a valve 156, a conduit 180 andagitation nozzles 166 in the first portion 104 of the hopper 102. Thesolution passes through the return tube 126 and returns to the hopper102. The finished product tube 128 passes to a storage tank 410 (seeFIG. 14). The diverter valve 136 may further comprise a manual override.

The dilute valve 134 is controlled by the PLC 216. The dilute valve 134may communicate with the solution pump 124. The dilute valve 134 thusactuates open to pass sufficient solvent to dilute the solution whenpump 124 is passing flow and the solution sensor 132 senses a solutionactual concentration over the target concentration. The dilute valve 134communicates with the solvent inlet 138. The dilute valve 134 actuatesopen when the pump 124 is passing flow and the solution sensor 132senses a solution actual concentration over a target concentration. Whendilute valve 134 is open, solvent from the solvent inlet 138 passesthrough the dilute valve 134 into the conduit 212 and into the diluteinlet 146. The solvent combines with the solution passing from thesecond portion 106 of the hopper 102 to the pump 124. The dilute valve134 allows sufficient solution to dilute the over-concentrated solutionreaches the target concentration and thus does not over-dilute thesolution. The dilute valve 134 may further comprise a manual override.

The sensed solution may be automatically diluted in any suitable mannerat any suitable point. For instance, the sensed solution may be dilutedvia addition of solvent to the outlet tube. Alternately, the sensedsolution may be diluted via return to the hopper and mixing with furthersolvent in the hopper.

A flow measuring device 204, shown in FIG. 12, may be provided formeasuring the volume of finished solution being transferred to thestorage tank. The flow measuring device 204 may be provided incommunication with the PLC 216. Further, an additive pump 210, flowmeasuring device 206, and actuated valve 208 may be provided to allowflow into a conduit 128. The additive pump 210, flow measuring device206, and actuated valve 208 may be in communication with the PLC 216 toenable mixing of an additive with the solution as it is transferred to astorage tank, as is discussed more fully below.

During use, solids such as dirt and silica may infiltrate the automatedsolution maker. These solids typically cause sediment build up insolution making machines. Generally, it is desirable for the solution tobe as clean as possible. Foreign material in the solution is abrasive.The abrasiveness can produce excess wear on pumps, flow meters andvalves associated with the production and application of the brinesolution. Sediment deposits caused by foreign material in suspension ofthe solution over time settle out and form layers of sediment in thestorage tank. Cleaning the sediment can be time consuming and canrequire the machine to be offline.

In one embodiment, the second portion 106 of the hopper 102 isconfigured for easy cleaning. The second portion 106 (see, for example,FIGS. 3 and 21) thus comprises at least one sloped plane along whichsediment slides to a sump located at the bottom of the sloped plane. Asuitable slope for the at least one sloped plane is approximately 15degrees. In the embodiment shown, the second portion 106 comprises afirst sloped plane 150, a second sloped plane 152, and a third slopedplain 202. Sediment that passes through the grate 142 collects on thebottom of the second portion 106 of the hopper in a sump area formed bythe first sloped plane 150, second sloped plane 152, and the thirdsloped plane 202. The sump area may be, for example, approximately 12inches by 12 inches.

A sump outlet 108 may be provided to allow the sediment to be flushedout of the hopper 102. Such flushing may be done via spray bars 402(shown, for example, in FIGS. 2 and 9) and a nozzle 162 (shown, forexample, in FIG. 3). A plurality of nozzles, for example a nozzleprovided on each wall to the left, right, and back side of the sump, maybe provided for forcing sediment through the sump and out of theautomated solution maker. The automated solution maker may be configuredfor automatic flushing of the sediment or for manual flushing of thesediment. Further, the sediment may be flushed from the hopper 102 whilethe chemical is in the first portion 104 of the hopper 102 or may beflushed from the hopper 102 when there is substantially no chemicalpresent in the first portion 104 of the hopper 102. The grate 142 in thehopper 102 supports the weight of the chemical, thus enabling thesediment to be flushed while the chemical is in the hopper 102.

Thus, the automated solution maker further provides a method forseparating foreign material such as undissolved silica, dirt, and gravelfrom the hopper 102. The foreign material may accumulate in a sump areafrom which the deposits may be flushed at a later time. Further, theautomated solution maker enables a flushing of deposits of foreignmaterial from the hopper while a chemical remains in the first portionof the hopper.

The automated solution maker, in some embodiments, may hold10,000-20,000 pounds of a chemical such as salt. Thus, the hopper 102 ismanufactured to be sufficiently strong to support the load. The hopper102 may be made of any suitable material. In one embodiment a suitablematerial from which the hopper 102 may be constructed is fiberglass.Fiberglass is strong and is not affected by salt solutions. Morespecifically, the hopper may be constructed of 16,000 lb tensilestrength fiberglass and isophthalic resin. Other suitable materials forthe hopper 102 include but are not limited to stainless steel andpolypropylene. The inside surfaces of the hopper may be coated with aceramic resin. Such coating may be, for example, approximately 0.050inches thick. Structural integral ribs may be provided within the hopperto limit flex to within one inch from fill to empty. In one embodiment,the overall thickness of fiberglass and resin in the hopper isapproximately 0.35 inches. Structural areas such as ribs, corners, andfloor may be provided with additional layers of woven fiberglass mat foran overall thickness of approximately 0.50 inches.

In use, the automated solution maker may be used by a highway departmentfor producing brine solution to deice roads. The automated solutionmaker may be used outdoors in cold weather. Thus, the automated solutionmaker may be provided with one or more of its components being heated.Heating elements 168 (see, for example, FIG. 3) may be provided in thehopper 102. A temperature sensing device may be provided in the hopper102 in communication with the PLC 216. The temperature sensing deviceindicates if the heating elements 168 need to be activated to raise thetemperature of the hopper 102. These elements may be thermostaticallyactivated on and off and capable of sustaining a temperature of 32degrees Fahrenheit or higher to prevent the vessel from freezing.

Thus, the hopper 102 may be heated to minimize the chance of the hopperfreezing in cold weather. In one embodiment, silicone mat heaters arebuilt into the hopper. For example, two nine-foot square silicone matsmay built into the hopper. A roll tarp such as a permanently mountedroll tarp may be used in conjunction with the heaters for heating thehopper. Such roll tarp may be provided with arches and a roll mechanismand is useful for keeping heat in and debris out. If provided, the rolltarp may be mounted over an open top of the hopper.

FIGS. 11-13 illustrates embodiments of a control panel of the automatedsolution maker. The control panel 500 may be comprised of mechanicalflow control devices, the conductivity sensor 132, the PLC 216, and thehuman-machine interface (HMI) 214. In another embodiment, the PLC 216 isin communication with HMI 214 to create a data log. Solution producedand diverted to the storage tank is measured via a flow measuring device204 (see, for example, FIG. 12) and recorded in the PLC program 216.This measurement may be via a flow meter of a flow switch. Calculationsmay be introduced into the PLC program 216 to formulate the amount ofsolution produced, the chemical usage, and the solvent usage in theproduction process. The data log thus creates reports that may be viewedon the HMI 214 or printed onto a printer. These reports may be createddaily and may show a running season total of solution produced as wellas chemical and solvent usage (and additive usage if an additive isintroduced into the solution). Multiple user reports may be generated.For example, a daily and season total may be created and tailored forseparate individuals for accounting and billing purposes.

The control panel enables regulation of solvent flow into the firstportion of the hopper. The solvent concentration and/or actualtemperature compensated concentration may be monitored and, if theconcentration is out of the tolerance for the target concentration, thesolution may be returned to the hopper. Alternately, the solution may bediluted mid-stream after exiting the hopper to meet the desiredconcentration level. Solution of a desired concentration may beprocessed to a holding tank. As shown, the PLC, conductivity analyzer,and other electric controls may be mounted in an electric enclosure onthe rear side of the panel. The main panel of the control panel mayinclude valve labels and valve functions. Information displayed on thescreen may include the actual production solution concentration in theform of % concentration by weight, the gallons of solvent used to makesolution, self-diagnostic of the conductivity sensor, self-diagnostic ofelectric valves (indicating if and what valve is not functioningnormally), valve status of open or closed, and status of the machinealong with the status of electrical components. In one embodiment, thedisplay is multi-colored with a green screen indicating system normal, ared screen indicating machine fault, and an orange screen indicatingsetup parameters.

The automated solution maker may be configured as self-diagnostic.Accordingly, the valves and sensors may be in operable communicationwith the controller to confirm the current state. In the event of acomponent failure, the system may be configured to automatically shutdown and provide information on the specific failure along with acorrective measure, including how to manually override problem and partnumber failure.

FIG. 14 illustrates flow of an automated solution maker in accordancewith one embodiment of the present invention. As shown, solvent 402,such as water, passes into the hopper 404. In the hopper 404, thesolvent mixes with a chemical, such as salt, to form a solution, such asbrine. The solution 406 exits the hopper 404. A conductivity sensor 408measures the conductivity of the exiting solution 406 and therebydetermines the concentration of the solution 406. If the concentrationis within the desired range, the solution 406 continues to a storagetank 410. If desired, an additive 412 may be added to the solution 406after it is determined to be at an acceptable concentration. If thesolution 406 is not at the desired concentration, it is returned 414 tothe hopper 404. This process is described more precisely below.

In operation, a chemical, for example rock salt, is deposited in thefirst portion 104 of hopper 102. The pump 124 is initially in the “off”state while the solvent valve 136 is in the “on” position. An operatorat the HMI 214 enters a desired target solution concentration, volume ofsolution to be produced, and, if desired, a ratio of additive in thefinished product. Upon entering this information, the operator activatesa start switch which activates the PLC program into the operation mode.The operation mode begins solvent flow from valve 136 into the hopper104. The first portion 104 of the hopper 102 receives solvent from sprayheads 178 via the solvent inlet 138, the actuated valve 136, the conduit200, the valve 186, the valve 158, and the conduit 176. The solventdissolves the chemical, and the formed solution passes through the grate142 into the second portion 106 of the hopper 102. Solvent continues toenter through the spray heads 178 into the hopper 102 until the thirdliquid level sensor 122 detects the hopper 102 is full of liquid andactivates the solvent valve 136 into the “off” position so that thehopper 102 does not overflow.

While the hopper 102 receives solvent, the second liquid level sensor120 detects whether an adequate amount of solvent is present in thehopper 102. When an adequate amount of solvent is present in the hopper102, the pump 124 is actuated into an “on” position. The pump 124 islatched into the “on” position until the batch is completed or the firstliquid level sensor 118 detects that the liquid level is low.

The pump 124 transfers the solution from the second portion 106 ofhopper 102 through the first suction tube 164, the conduit 188, thevalve 154, conduit, dilute inlet 146 and into the suction side inlet ofthe pump 124. The pump 124 may be configured to pump approximately 5,000gallons of solution per hour with a dynamic head of 45 feet.

The solution sensor 132 senses the conductivity and the temperature ofthe solution transferred by the pump 124 from the hopper 106. Thesolution sensor 132 measures the electrical resistance of the solutionflowing across the solution sensor 132. This measurement may be done bya probe and conductivity analyzer of the solution sensor 132. Theelectrical resistance is compared to the temperature of the solution andthese two variables are equated to form a temperature compensatedconductivity reading. This reading is equated to a chemicalconcentration curve which in turn expresses the reading of the solutionas a temperature compensated concentration by weight. A concentrationcurve correlating temperature compensated conductivity to concentrationmay be developed for any chemicals in solution. Thus, for example, in anautomated brine maker, a sodium chloride concentration curve is used.

If the solution is over-concentrated the conductivity analyzer thencommunicates with the PLC 216; which in turn opens the dilute valve 134to permit solvent to dilute the over-concentrated solution exiting thehopper 106 to the target concentration. When the dilute valve 134 isactivated, solvent from the solvent inlet 138 passes through the dilutevalve 134 and into the dilute inlet 146 and combines with the solutionpassing from the second portion 106 of the hopper 102 to the pump 124.The dilute valve 134 remains activated until the solution reaches thetarget concentration. The over-concentrated solution is diverted fromthe pump 124 by the diverter valve 130 and passes through the returntube 126 into the first portion 104 of the hopper 102 via the conduit180, valve 156 and agitation nozzles 166.

If the solution is under-concentrated, the under-concentrated solutionis diverted from the pump 124 by the diverter valve 130 and passesthrough the return tube 126 into the first portion 104 of the hopper 102via valve 156, conduit 180, and agitation nozzles 166.

If the solution is within a tolerance level of a target concentration,the solution is diverted from the pump 124 by the diverter valve 130 andpasses through the finished product tube 128 and into a storage tank(not shown). Optionally, if trucks are being loaded with solution duringoperation of the automated solution maker, solution within a tolerancelevel of a target concentration may be diverted directly to the a truckvia a truck fill hose. When diverting solution to a storage tank, aremove till electric plug wiring harness may be provided toautomatically shut off filling of the storage tank when full. Thus, asensing device may be provided for sensing the state of the storagetank.

Over time the liquid level drops in the hopper 102 due to solutionwithin the tolerance level of the target concentration being sent to thestorage tank. First liquid level sensor 118 detects if the water levelin hopper 102 is low and turns pump 124 to the “off” state if theautomated solution maker 100 is in operate mode. Alternately, solventand chemicals may be continuously provided to the automated solutionmaker. In a semi-continuous embodiment, the automated solution maker 100continuously produces solution of a desired concentration. Thus, theautomated solution maker 100 may be configured for continuous batchprocessing. Continuous batch processing enables production of moresolution per amount of time the automated solution maker is running.

The configuration of the automated solution maker thus offers a downwardflow design. In the first portion 104 of the hopper 102, solvent flowsdownwardly through the chemical to form the solution. The solutionpasses through the grate 142, into the second portion 106. The solutionwith the highest concentration settles to the bottom of the secondportion 106 where the solution is removed for processing.

A data log may be generated by the automated solution maker forrecording how much solution is produced and the quantity of ingredients(chemical and solvent) used.

FIGS. 3, 5, and 20 further illustrate the easy cleaning aspect of theautomated solution maker.

FIGS. 3, 5, and 21 illustrate the sloping surfaces and sump of thesecond portion 106 of the hopper 102. Due to the sloping surfaces,sediment that passes through the grate 142 collects on the bottom of thesecond portion in an area adjacent a sump outlet 108. Any suitablenumber of sloping surfaces may be used. In the embodiment shown, a firstsloped plane 150, a second sloped plane 152 and a third sloped plain 202are provided. Thus, sediment that passes through the grate 142 collectson the bottom of the second portion 106 of the hopper in an area formedby the first sloped plane 150, the second sloped plane 152 and the thirdsloped plane 202. The sump outlet 108 allows the sediment to be flushedfrom the hopper 102 using the spray bars 402 and nozzles 162, asdescribed above.

FIGS. 2-4 illustrate the hopper 102. The hopper comprises a firstportion 104 and a second portion 106. Nozzles 162 are provided on thesecond portion 106. The nozzles 162 spray a liquid substantially in thedirection of sump outlet 108, provided in the second portion 106. In oneembodiment, the liquid that is sprayed by the nozzles 162 is water.Thus, liquid is expelled from the nozzles 162 and directed towardssediment accumulated adjacent the sump outlet 108. Force from the sprayforces the sediment to pass through the sump outlet 108. Of course, anyother suitable means for forcing the sediment through the sump outletmay be used.

As further illustrated by FIGS. 19 and 20, the first portion 104 of thehopper 102 may include a spray head 178. Alternately, the first portion104 may include a plurality of spray heads. The spray head 178 receivessolvent from the solvent inlet 138 via the solvent valve 136.

FIGS. 6 and 9 illustrate a plurality of spray bars 402 (only one sideshown) that are located on opposite sides of second portion 106 of thehopper 102. The spray bars 402 spray a liquid that forces sedimenttowards the sump outlet 108.

As discussed above, during use of the automated solution maker, sedimentmay pass through the grate 142 into the second portion 106 of the hopper102. Sediment that settles on first sloped plane 150 and second slopedplane 152 is forced downward towards the bottom of second portion 106via spray bars 402 that are positioned along the first sloped plane 150and the second sloped plane 152. The spray bars 402 are supplied withliquid via liquid supply 138, conduit 200, water inlet 186, flush valve160, and conduit 174. The sediment that is located in the bottom ofsecond portion 106 is forced out of the sump outlet 108 of the secondportion 106 via the nozzle 162. Liquid is supplied to the nozzle 162 vialiquid supply 138, conduit 200, water inlet 162, and conduit 172.

The chemical is supported within the first portion 104 by the grate 142.Thus, the sediment may be flushed from the hopper 102 while chemical isin the first portion 104 of the hopper 102. Alternately, the sedimentmay be flushed from the hopper 102 when there is substantially nochemical in the first portion 104 of the hopper 102.

FIG. 12 illustrates a control panel for an automated solution makerwherein an additive may be supplied to the solution. Thus, the automatedsolution maker may be used to inject an additive into the desiredsolution concentration at a desired ratio. For example, when theautomated solution maker is used to make brine, additives that makebrine work at lower temperatures or reduce the corrosiveness of brinemay be beneficial.

Typically brine is used at approximately 20 degrees Fahrenheit or above.By mixing additives with the brine, the effective temperature for usingbrine may be reduced to approximately 0 degrees Fahrenheit, therebyproviding a solution of melting snow and ice at lower temperatures. Saltbrine is naturally corrosive and the corrosive nature of the brine leadsto corrosion of bridge decks, vehicles, and roadways. Reducing thecorrosive nature of brine and lowering the freezing point of brine bymixing at least one additive at a predefined ratio into the brine hasbenefits to the environment. Generally, these additives are costlycompared to the cost of brine solution. It is desirable to provide anautomated apparatus for injecting a desired amount of additive into thesolution when needed and thus reduce cost and enable an enriched productto be produced when needed.

Using the embodiment of FIG. 12, a user enters a desired percentage oftotal volume in which an additive is to be processed via the HMI 214 tothe storage tank where the finished product is stored. As brine isproduced and diverted to the storage tank, a predetermined ratio ofadditive is placed into the conduit 128 via the pump 210 controlled bythe PLC 216 connected to a supply tank for the additive (not shown). Thepump 210 transports the solution. A flow meter 206 is in communicationwith the PLC 216 and measures the additive volume. An actuated valve toshut off flow is controlled by the PLC 216.

Thus, in the embodiment shown in FIG. 12, a solution may be produced atdesired concentrations and, as the solution is transported to a holdingtank, a desired ratio of additive based on volume of solution may bemixed with the solution. This ratio may be between 0 and 100%, asdesired. The automated solution maker thus produces brine and has theability to automatically mix and inject any ratio of additive into thesolution.

FIG. 16 illustrates a perspective view of the float assembly on thehopper.

FIG. 17 illustrates solvent being added to a first portion 104 of anautomated solution maker via spray heads 178. FIG. 18 illustrates mixingof the solvent with the chemical in the first portion 104 of theautomated solution maker.

Although the present invention has been described with reference toembodiments, persons skilled in the art will recognize that changes maybe made in form and detail without departing from the spirit and scopeof the invention.

1. A method for automatically producing a solution, the methodcomprising: depositing a chemical in a hopper; adding a solvent to thehopper, wherein the chemical at least partially dissolves in the solventto form a solution; measuring a conductivity of the solution andcorrelating the conductivity of the solution to a concentration toestablish a concentration of the solution; comparing the concentrationof the solution to a target concentration; automatically diluting thesolution if the solution is over-concentrated; automatically increasingthe concentration of the solution if the solution is under-concentrated;and automatically diverting the solution to a storage tank of thesolution concentration is within tolerance of the target concentration.2. The method of claim 1, further comprising measuring a temperature ofthe solution and determining a temperature compensates concentration byweight of the solution.
 3. The method of claim 1, further comprisingpumping the solution from the hopper into the outlet tube, wherein theconductivity of the solution is measured in the outlet tube.
 4. Themethod of claim 1, wherein automatically diluting the solution comprisesadding solvent to the solution within the outlet tube and whereinautomatically increasing the concentration of the solution comprisesreturning the solution to the hopper.